Large-aperture continuous zoom camera optical system

Abstract

The invention discloses an optical system of a large-aperture continuous zoom camera. The large-aperture continuous zoom camera optical system comprises a large objective lens group, a zoom lens group, a first compensating lens group, a focusing lens group, a first reflecting mirror, a second compensating lens group, a third compensating lens group, a filter lens group and a second reflecting mirror which are sequentially arranged along the direction of an optical axis, the large objective lens group is provided with a first lens, a second lens and a third lens; the zoom lens group is provided with a first balsaming lens and a sixth lens; the first compensating lens group is provided with a seventh lens and a second bonding lens; the focusing lens group is provided with a third bonding lens; the second compensating lens group is provided with a twelfth lens and a fourth bonding lens; and the third compensating lens group is provided with a fifth bonding lens. Through mutual cooperation of the zoom lens group, the compensation lens group and the focusing lens group, the optical structure is simple, the aperture is large, the focal length is long, the axial size is short, the stability is high, the environmental adaptability is good, the image quality is excellent, and the lens can be completely matched with various high-definition imaging assemblies.

Description

Technical Field

[0001] The invention relates to the technical field of optical imaging, and in particular to an optical system of a large-aperture continuous zoom camera. Background Art

[0002] Camera systems are widely used in airborne or vehicle-mounted search, aiming and indication systems due to their long range, large zoom ratio and wide spectrum. The system's large field of view can search for targets in a large range, greatly improving the probability of capturing the target. Once the target is locked, the camera system can quickly adjust to a small field of view to accurately identify and track the target. During the field of view conversion process, the system can maintain the continuity of the image, effectively overcoming the short-term target blur that may occur during the traditional two-speed or multi-speed lens switching process, and has significant advantages in searching and tracking high-speed moving targets.

[0003] However, the camera systems disclosed in the prior art have certain limitations, such as small aperture, long axial dimension, complex system structure and short focal length, which are not conducive to detecting and identifying targets at long distances.

[0004] Therefore, it is particularly important to develop a large-aperture continuous zoom camera optical system. This new camera system will better meet the needs of long-distance, high-precision target detection and recognition. Summary of the invention

[0005] The purpose of this application is to overcome the above-mentioned technical deficiencies and propose a large-aperture continuous zoom camera optical system, which has the characteristics of large aperture, long focal length, simple structure, short axial size, high stability, good environmental adaptability and good imaging quality, and solves the technical problems of small aperture, long axial size, complex system structure and short focal length in the prior art.

[0006] In order to achieve the above technical objectives, this application adopts the following technical solutions: The present application provides a large-aperture continuous zoom camera optical system, comprising a large objective lens group, a zoom lens group, a first compensation lens group, a focusing lens group, a first reflector, a second compensation lens group, a third compensation lens group, a filter lens group and a second reflector arranged in sequence along the optical axis direction; The large objective lens group is provided with a first lens, a second lens and a third lens in sequence along the optical axis direction; The zoom lens group is provided with a first cemented lens and a sixth lens in sequence along the optical axis direction; The first compensation lens group is provided with a seventh lens and a second cemented lens in sequence along the optical axis direction; The focusing lens group is provided with a third cemented lens; The second compensation lens group is provided with a twelfth lens and a fourth cemented lens in sequence along the optical axis direction; The third compensation lens group is provided with a fifth cemented lens.

[0007] In some embodiments of the present application, the first lens includes a meniscus lens with negative optical focal length, the second lens includes a biconvex lens with positive optical focal length, the third lens includes a biconvex lens with positive optical focal length, the material of the first lens includes H-ZLAF69, the material of the second lens includes H-FK61B, and the material of the third lens includes H-FK95N.

[0008] In some embodiments of the present application, the first cemented lens includes a meniscus lens with positive optical focal length and a biconcave lens with negative optical focal length arranged in sequence along the optical axis direction, the sixth lens includes a meniscus lens with negative optical focal length, the material of the first cemented lens includes H-ZF88 and H-QK3L, and the material of the sixth lens includes H-LAK52.

[0009] In some embodiments of the present application, the seventh lens includes a biconvex lens with positive focal power, the second cemented lens includes a meniscus lens with negative focal power and a biconvex lens with positive focal power arranged in sequence along the optical axis, the material of the seventh lens includes H-LAK11, and the materials of the second cemented lens include H-FK95N and H-ZF52GT respectively.

[0010] In some embodiments of the present application, the third cemented lens includes a biconvex lens with positive optical power and a biconcave lens with negative optical power sequentially arranged along the optical axis, and the materials of the third cemented lens include H-FK61B and H-LAK11, respectively.

[0011] In some embodiments of the present application, the twelfth lens includes a biconvex lens with positive focal power, the fourth cemented lens includes a biconcave lens with negative focal power and a meniscus lens with positive focal power arranged in sequence along the optical axis, the material of the twelfth lens includes H-ZF88, and the materials of the fourth cemented lens include H-ZLAF69 and H-QK3L respectively.

[0012] In some embodiments of the present application, the fifth cemented lens includes a biconvex lens with positive optical power and a meniscus lens with negative optical power, and the materials of the fifth cemented lens include H-QK3L and H-ZF88 respectively.

[0013] In some embodiments of the present application, the filter group is provided with a visible light filter, a near-infrared filter, a narrow-band filter, and a polarized light filter in sequence. The material of the visible light filter includes H-K9L, the material of the near-infrared filter includes HB760, the material of the narrow-band filter includes HB850, and the material of the polarized light filter includes H-K9L.

[0014] In some embodiments of the present application, the axial movement size of the variable magnification lens group is greater than the axial movement size of the first compensation lens group, and the axial movement range of the focusing lens group is +10mm to -20mm.

[0015] In some embodiments of the present application, the focal length of the variable magnification lens group is -80mm<f<-50mm, the focal length of the first compensation lens group is 90mm<f<120mm, and the focal length of the focusing lens group is -150mm<f<-100mm.

[0016] Compared with the prior art, the technical solution provided by this application has the following beneficial technical effects: The embodiment of the present application uses a large objective lens group to converge the target scene light at the focus of the zoom lens group, and the zoom lens group realizes the continuous zoom of the camera. The first compensation lens group compensates for the zoom aberration of the zoom lens group, the focusing lens group compensates for the defocus amount generated under the full field of view and the small field of view, and the second compensation lens group and the third compensation lens group compensate for the residual aberration. The priority matching of lens materials and shapes effectively reduces and balances various aberrations, and the optical system has a simple structure and a small number of lenses, ensuring good imaging during the zoom process. Through the cooperation of the zoom lens group, the compensation lens group, and the focusing lens group, the axial length of the system and the imaging quality are effectively controlled, making the system structure compact. By adopting the design and adjustment method of internal focusing, not only the stability of the system is guaranteed, but also the environmental adaptation of the full field of view and the small field of view is met. By adopting the sixteen-piece optical structure layout form, the design difficulty of the system is reduced, and the continuous zoom of the optical system of the large-aperture continuous zoom camera is realized, and the optical structure is simple, the aperture is large, the focal length is long, the axial size is short, the stability is high, the environmental adaptability is good, and the image quality is excellent, which can fully match various high-definition imaging components. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solution in this application, the following is a brief introduction to the drawings required for use in the embodiments: Figure 1 It is a structural schematic diagram of a large-aperture continuous zoom camera optical system provided in an embodiment of the present application at a focal length of 55 mm; Figure 2 It is a structural schematic diagram of a large-aperture continuous zoom camera optical system at a focal length of 1350 mm provided in an embodiment of the present application.

[0018] Reference numerals: 1-large objective lens group, 2-variator lens group, 3-first compensation lens group, 4-focusing lens group, 5-first reflector, 6-second compensation lens group, 7-third compensation lens group, 8-filter lens group, 9-second reflector, 10-aperture; 11-a first lens, 12-a second lens, 13-a third lens, 21-a fourth lens, 22-a fifth lens, 23-a sixth lens, 31-a seventh lens, 32-a eighth lens, 33-a ninth lens, 41-a tenth lens, 42-a eleventh lens, 61-a twelfth lens, 62-a thirteenth lens, 63-a fourteenth lens, 71-a fifteenth lens, 72-a sixteenth lens. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0020] Those skilled in the art will appreciate that in this specification, the wording "including" is an open-ended expression, which means that the described features exist but does not exclude other features. The directional words "up", "down", "left", "right", etc. are exemplary directions based on the drawings. Features defined as "first" and "second" implicitly include one or more of the features. Singular expressions can also be used in the plural. "Multiple" means two or more. The terms "installed", "connected", and "connected" can be fixed connections, detachable connections, or integrated connections; they can be directly connected, or indirectly connected through an intermediate medium, or they can be internal connections between two elements. In addition, "connected" can include wireless connections.

[0021] The purpose of this application is to overcome the above-mentioned technical deficiencies and propose a large-aperture continuous zoom camera optical system, which has the characteristics of large aperture, long focal length, simple structure, short axial size, high stability, good environmental adaptability and good imaging quality, and solves the technical problems of small aperture, long axial size, complex system structure and short focal length in the prior art.

[0022] In order to achieve the above technical objectives, this application adopts the following technical solutions: The present application provides a large-aperture continuous zoom camera optical system, such as Figure 1 and Figure 2 As shown, Figure 1 It is a structural schematic diagram of a large-aperture continuous zoom camera optical system provided in an embodiment of the present application at a focal length of 55 mm; Figure 2 It is a structural schematic diagram of a large-aperture continuous zoom camera optical system at a focal length of 1350 mm provided in an embodiment of the present application.

[0023] An optical system of a large-aperture continuous zoom camera comprises a large objective lens group 1, a variable magnification lens group 2, a first compensation lens group 3, a focusing lens group 4, a first reflector 5, a second compensation lens group 6, a third compensation lens group 7, a filter lens group 8 and a second reflector 9 which are sequentially arranged along the optical axis direction; The large objective lens group 1 is provided with a first lens 11, a second lens 12 and a third lens 13 in sequence along the optical axis direction; The zoom lens assembly 2 is provided with a first cemented lens and a sixth lens 23 in sequence along the optical axis direction; The first compensation lens group 3 is provided with a seventh lens 31 and a second cemented lens in sequence along the optical axis direction; The focusing lens group 4 is provided with a third cemented lens; The second compensation lens group 6 is provided with a twelfth lens 61 and a fourth cemented lens in sequence along the optical axis direction; The third compensation lens group 7 is provided with a fifth cemented lens.

[0024] In the embodiment of the present application, the target scene light is converged at the focus of the zoom lens group 2 through the large objective lens group 1, and the zoom lens group 2 realizes the continuous zoom of the camera. The first compensation lens group 3 compensates for the zoom aberration of the zoom lens group 2, and the focusing lens group 4 compensates for the defocus amount generated under the full field of view and the small field of view. The second compensation lens group 6 and the third compensation lens group 7 compensate for the residual aberration. The priority matching of lens materials and shapes effectively reduces and balances various aberrations, and the optical system structure is simple and the number of lenses is small, which ensures good imaging during the zoom process. Through the cooperation between the zoom lens group 2, the compensation lens group, and the focusing lens group 4, the axial length of the system and the imaging quality are effectively controlled, making the system structure compact. By adopting the design and adjustment method of internal focusing, not only the stability of the system is guaranteed, but also the environmental adaptation under the full field of view and the small field of view is met. By adopting a sixteen-piece optical structure layout, the design difficulty of the system is reduced, and the continuous zoom of the large-aperture continuous zoom camera optical system is achieved. The optical structure is simple, the aperture is large, the focal length is long, the axial size is short, the stability is high, the environmental adaptability is good, and the image quality is excellent. It can fully match various high-definition imaging components.

[0025] In this embodiment, the focal length range of the optical system of the large-aperture continuous zoom camera is 55 mm to 1350 mm, the zoom ratio is 24.6 times, the F number is 5 to 8.5, and the axial dimension is 460 mm.

[0026] In some embodiments of the present application, the first lens 11 includes a meniscus lens with negative optical power, the second lens 12 includes a biconvex lens with positive optical power, the third lens 13 includes a biconvex lens with positive optical power, the material of the first lens 11 includes H-ZLAF69, the material of the second lens 12 includes H-FK61B, and the material of the third lens 13 includes H-FK95N.

[0027] In this embodiment, the function of the large objective lens group 1 is to converge the target scene light at the focus of the zoom lens group 2 (2). The refractive indices corresponding to the materials H-ZLAF69, H-FK61B, and H-FK95N are 1.816, 1.497, and 1.438, respectively, and the Abbe numbers are 46.55, 81.61, and 94.52, respectively.

[0028] Optionally, the outer diameter of the large objective lens group 1 is 165 mm.

[0029] In the first lens 11, the meniscus lens with negative optical power can effectively control spherical aberration and coma, so that the light entering the system can be better converged, thereby improving the imaging quality. H-ZLAF69 is a high refractive index and high dispersion optical glass.

[0030] In the second lens 12 and the third lens 13, the biconvex lens with positive focal power helps to converge light, reduce astigmatism and field curvature, and thus provide uniform imaging performance throughout the field of view. H-FK61B is a low refractive index and low dispersion optical glass, and H-FK95N is an ultra-low refractive index and ultra-low dispersion optical glass. The refractive index and dispersion of the three materials are different, but the mutual priority of the refractive index and Abbe number of the three materials has good achromatic and apochromatic capabilities, which can effectively improve the imaging quality and meet the requirements of high-performance optical system design.

[0031] In order to achieve a focal length range of 55mm to 1350mm, the traditional large-aperture continuous zoom camera optical system generally selects four to five lenses, and the lens materials are usually H-LAF54, H-FK61B, H-LAF4GT, and H-QK3L. This design not only requires a large number of large objective lenses, but is also not conducive to system achromatism and apochromatism.

[0032] In some embodiments of the present application, the first cemented lens includes a meniscus lens with positive focal power and a biconcave lens with negative focal power sequentially arranged along the optical axis direction, the sixth lens 23 includes a meniscus lens with negative focal power, the material of the first cemented lens includes H-ZF88 and H-QK3L, and the material of the sixth lens 23 includes H-LAK52.

[0033] In this embodiment, the function of the zoom lens group 2 is to realize the continuous zoom of the camera. The first cemented lens is formed by gluing the fourth lens 21 and the fifth lens 22 by photosensitive adhesive. The refractive indexes of the materials H-ZF88, H-QK3L, and H-LAK52 are 1.946, 1.488, and 1.729, respectively, and the Abbe numbers are 17.94, 70.44, and 54.69, respectively.

[0034] Optionally, the outer diameter of the glass in the zoom lens assembly 2 is 50 mm.

[0035] In the first cemented lens, the fourth lens 21 adopts a meniscus lens with positive focal length, which helps to reduce spherical aberration and coma and improve image clarity. The H-ZF88 adopted is a high refractive index and high dispersion optical glass.

[0036] The fifth lens 22 is a double concave lens with negative focal power, which is glued to a meniscus lens with positive focal power, which can further balance aberrations, especially reduce chromatic aberrations, thereby improving the imaging quality of the entire optical system. The H-QK3L used is a low refractive index and low dispersion optical glass.

[0037] In the sixth lens 23, the meniscus lens with negative focal length helps to control spherical aberration and coma, especially to maintain image clarity and contrast during zooming. H-LAK52 is a medium refractive index and medium dispersion optical glass. The refractive index and dispersion of the three individual materials are different, but the mutual priority of the refractive index and Abbe number of the three materials is conducive to correcting the system's high-level aberrations and ensuring good imaging during zooming.

[0038] In some embodiments of the present application, the seventh lens 31 includes a biconvex lens with positive optical power, the second cemented lens includes a meniscus lens with negative optical power and a biconvex lens with positive optical power arranged in sequence along the optical axis, the material of the seventh lens 31 includes H-LAK11, and the materials of the second cemented lens include H-FK95N and H-ZF52GT respectively.

[0039] In this embodiment, the first compensation lens group 3 is used to compensate for the variable magnification aberration of the variable magnification lens group 2. The second cemented lens is formed by gluing the eighth lens 32 and the ninth lens 33 by photosensitive adhesive. The refractive indices corresponding to the materials H-LAK11, H-FK95N, and H-ZF52GT are 1.665, 1.438, and 1.847, respectively, and the Abbe numbers are 54.61, 94.52, and 23.78, respectively.

[0040] Optionally, the outer diameter of the glass in the first compensation lens group 3 is 48 mm.

[0041] In the seventh lens 31, the biconvex lens with positive power helps to converge light, reduce spherical aberration and coma, and thus improve the imaging quality. H-LAK11 is a medium refractive index and medium dispersion optical glass.

[0042] In the second cemented lens, the eighth lens 32 adopts a meniscus lens with negative optical power, which helps to control spherical aberration and coma and maintain image clarity and contrast. The H-FK95N adopted is an ultra-low refractive index and ultra-low dispersion optical glass.

[0043] The ninth lens 33 uses a double convex lens with positive focal power to help converge light, reduce astigmatism and field curvature, thereby providing uniform imaging performance throughout the field of view, and the H-ZF52GT used is a high refractive index and high dispersion optical glass; this combination design of the eighth lens 32 and the ninth lens 33 can effectively balance and compensate for aberrations, especially chromatic aberrations, thereby maintaining image clarity and contrast throughout the zoom range. The combination of the seventh lens 31 and the second cemented lens is similar to that in the above embodiment. The three lenses and the three materials cooperate with each other in priority, which is conducive to correcting the system's high-level aberrations and ensuring good imaging during the zoom process.

[0044] In some embodiments of the present application, the third cemented lens includes a biconvex lens with positive optical power and a biconcave lens with negative optical power sequentially arranged along the optical axis, and the materials of the third cemented lens include H-FK61B and H-LAK11, respectively.

[0045] In this embodiment, the function of the focusing lens group 4 is to compensate for the defocus when the system operates in the temperature range of -55℃ to +70℃ and observes a close-range target under a small field of view. The third cemented lens is formed by gluing the tenth lens 41 and the eleventh lens 42 together with a photosensitive adhesive. The refractive indices of the materials H-FK61B and H-LAK11 are 1.497 and 1.665, respectively, and the Abbe numbers are 81.61 and 54.61, respectively.

[0046] Optionally, the outer diameter of the glass in the focusing lens group 4 is 37 mm.

[0047] In the tenth lens 41, a double convex lens with positive focal power is used to effectively converge light, reduce spherical aberration, and improve image clarity, and the H-FK61B used is a low refractive index and low dispersion optical glass.

[0048] In the eleventh lens 42, a double concave lens with negative optical power is glued with a double convex lens with positive optical power, which helps to balance aberrations, especially reduce chromatic aberration and coma, thereby providing uniform imaging performance in the entire field of view, and the H-LAK11 used is a medium refractive index and medium dispersion optical glass; the lens in the focusing lens group 4 is small in size, light in weight, low in sensitivity, and simple in structure, and thus the required adjustment mechanism for driving the focusing lens group 4 to move back and forth along the optical axis is small in size, light in weight, and highly stable.

[0049] In some embodiments of the present application, the twelfth lens 61 includes a biconvex lens with positive focal power, the fourth cemented lens includes a biconcave lens with negative focal power and a meniscus lens with positive focal power arranged in sequence along the optical axis, the material of the twelfth lens 61 includes H-ZF88, and the materials of the fourth cemented lens include H-ZLAF69 and H-QK3L respectively.

[0050] In this embodiment, the second compensation lens group 6 is used to compensate for the residual aberration of the zoom lens group 2, the first compensation lens group 3 and the focusing lens group 4. The fourth cemented lens is formed by gluing the thirteenth lens 62 and the fourteenth lens 63 by photosensitive adhesive. The refractive indices corresponding to the materials H-ZF88, H-ZLAF69 and H-QK3L are 1.946, 1.816 and 1.488 respectively, and the Abbe numbers are 17.94, 46.55 and 70.44 respectively.

[0051] Optionally, the outer diameter of the glass in the second compensation lens group 6 is 35 mm.

[0052] In the twelfth lens 61, a double convex lens with positive focal length is used, which can effectively converge light, reduce spherical aberration, and improve image clarity and contrast. The H-ZF88 used is a high refractive index and high dispersion optical glass.

[0053] In the fourth cemented lens, the thirteenth lens 62 is a double concave lens with negative focal length, and the H-ZLAF69 used is a high refractive index and high dispersion optical glass. The fourteenth lens 63 is a meniscus lens with positive focal length, and the H-QK3L adopted is a low refractive index and low dispersion optical glass. The mutual priority coordination of the refractive index and Abbe number of the three materials effectively reduces and corrects the vertical axis chromatic aberration of the system, ensuring good imaging in each field of view.

[0054] In some embodiments of the present application, the fifth cemented lens includes a biconvex lens with positive optical power and a meniscus lens with negative optical power, and the materials of the fifth cemented lens include H-QK3L and H-ZF88 respectively.

[0055] In this embodiment, the third compensation lens group 7 is used to compensate for the residual aberration of the second compensation lens group 6; the fifth cemented lens is formed by gluing the fifteenth lens 71 and the sixteenth lens 72 by photosensitive adhesive. The refractive indices of materials H-QK3L and H-ZF88 are 1.488 and 1.946, respectively, and the Abbe numbers are 70.44 and 17.94, respectively.

[0056] Optionally, the outer diameter of the glass in the third compensation lens group 7 is 18 mm.

[0057] The fifteenth lens 71 uses a biconvex lens with positive focal length, which can effectively converge light, reduce spherical aberration, and improve image clarity and contrast. The H-QK3L used is a low-refractive-index and low-dispersion optical glass, which helps to reduce chromatic aberration and improve image quality.

[0058] In the sixteenth lens 72, a meniscus lens with negative focal power is used, which is cemented with a biconvex lens with positive focal power, which helps to balance aberrations, especially reduce chromatic aberration and coma, thereby providing uniform imaging performance throughout the field of view. The H-ZF88 used is a high-refractive-index and high-dispersion optical glass; it has good thermal stability and mechanical properties, which helps to maintain the shape and position stability of the lens. Through this lens combination and material selection, various aberrations can be effectively reduced, providing high-definition and high-contrast images, especially during continuous zooming.

[0059] In some embodiments of the present application, the filter group 8 is provided with a visible light filter, a near-infrared filter, a narrow-band filter, and a polarized light filter in sequence. The material of the visible light filter includes H-K9L, the material of the near-infrared filter includes HB760, the material of the narrow-band filter includes HB850, and the material of the polarized light filter includes H-K9L.

[0060] In this embodiment, the function of the filter group 8 is to switch through the filter mechanism to achieve imaging in four modes: visible light, near infrared, 1064nm laser spot monitoring, and polarized light.

[0061] Optionally, the outer diameter of the glass in the filter group 8 is 24 mm.

[0062] Also optionally, the thicknesses of the four filters are: 2.3mm, 2.1mm, 2.1mm, and 2.3mm respectively.

[0063] In some embodiments of the present application, the function of the first reflector 5 is to reflect the light entering the system at 45 degrees, thereby reducing the lateral size of the system and making the system structure compact.

[0064] The function of the second reflector 9 is to reflect the light entering the system at 45 degrees, thereby reducing the longitudinal size of the system and making the system structure compact.

[0065] In some embodiments of the present application, the axial movement size of the variable power lens group 2 is greater than the axial movement size of the first compensation lens group 3, and the axial movement range of the focusing lens group 4 is +10 mm to -20 mm.

[0066] In this embodiment, when the focal length is 55mm and 1350mm, the intervals between the large objective lens group 1 and the zoom lens group 2 are 83.65mm and 198.65mm respectively; the intervals between the zoom lens group 2 and the first compensation lens group 3 are 196.95mm and 2.25mm respectively; the intervals between the first compensation lens group 3 and the diaphragm 10 are 2.02mm and 81.72mm respectively, and the diaphragm 10 is located between the first compensation module and the focusing module. The axial movement size of the zoom lens group 2 is 115mm; the axial movement size of the first compensation lens group 3 is 79.7mm; and the axial movement range of the focusing lens group 4 is +10mm to -20mm.

[0067] In some embodiments of the present application, the focal length of the variable magnification lens group 2 is -80mm<f<-50mm, the focal length of the first compensation lens group 3 is 90mm<f<120mm, and the focal length of the focusing lens group 4 is -150mm<f<-100mm.

[0068] In this embodiment, a first lens 11, a second lens 12, a third lens 13, a first cemented lens, a sixth lens 23, a seventh lens 31, a second cemented lens, a third cemented lens, a twelfth lens 61, a fourth cemented lens, and a fifth cemented lens are sequentially arranged along the optical axis. The preferred combination of lens materials and shapes effectively reduces and balances various aberrations, and the optical system has a simple structure and a small number of lenses, thereby ensuring good imaging during the magnification change process.

[0069] In this embodiment, the zoom lens group 2, the first compensation lens group 3, and the focusing lens group 4 cooperate with each other, and the focal length of the zoom lens group 2 is designed to be -80mm<f<-50mm, the focal length of the compensation lens group is designed to be 90mm<f<120mm, and the focal length of the focusing lens group 4 is designed to be -150mm<f<-100mm, thereby effectively controlling the system axial length and imaging quality, making the system structure compact.

[0070] In this embodiment, by adopting the design and adjustment method of internal focusing, and the adjustment amount is +10mm~-20mm, not only the stability of the system is guaranteed, but also the requirements of clear imaging in the temperature range of -55℃~+70℃ of the whole field of view and observation of close targets of 30m~50m in a small field of view are met.

[0071] The traditional camera focusing mode generally selects the large objective lens group 1 to move forward and backward along the axis through the structural parts to focus, compensating for the defocus of small field of view, high and low temperature and close-range target observation. This method of focusing with the large objective lens group 1 has two disadvantages: 1) As can be seen from the system diagram, the large objective lens group 1 has a large aperture and heavy weight, and the stability is poor when it is moved forward and backward along the optical axis through the structural parts; 2) Since the eccentricity of the three objective lenses affects the imaging quality of the system, the matching clearance between the three objective lenses and the structural parts needs to be controlled at 0.008um. The clearance is small, and at a low temperature of -55℃, there is a phenomenon of mechanism locking and stagnation.

[0072] This patent adopts a sixteen-piece optical structure layout, which effectively reduces the design difficulty of the system and realizes continuous zoom of the camera optical system from 55mm to 1350mm. It has a simple optical structure, large aperture, long focal length, short axial size, high stability, good environmental adaptability, and excellent image quality, and can fully match various high-definition imaging components.

[0073] The axial length and imaging quality of the system are effectively controlled by the cooperation of the zoom lens group 2, the first compensation lens group 3, and the focusing lens group 4, making the system structure compact. By adopting the design and adjustment method of internal focusing, and the adjustment amount is +10mm~-20mm, not only the stability of the system is guaranteed, but also the environmental adaptability is met. The current camera systems on the market have small apertures, long axial dimensions, complex system structures, and short focal lengths, which are not conducive to long-distance target detection and identification.

[0074] It can be seen from the corresponding point diagram and transfer function diagram of this embodiment when the focal length is 55mm and 1350mm that various aberrations at different focal lengths are well corrected, the on-axis diffuse spot is less than 1 pixel, and the on-axis MTF is close to the diffraction limit (100lp / mm), which has met the basic requirements for the design of a continuous zoom system and has good imaging quality.

[0075] Compared with the prior art, the technical solution provided by this application has the following beneficial technical effects: In the embodiment of the present application, the target scene light is converged at the focus of the zoom lens group 2 through the large objective lens group 1, and the zoom lens group 2 realizes the continuous zoom of the camera. The first compensation lens group 3 compensates for the zoom aberration of the zoom lens group 2, and the focusing lens group 4 compensates for the defocus amount generated under the full field of view and the small field of view. The second compensation lens group 6 and the third compensation lens group 7 compensate for the residual aberration. The priority matching of lens materials and shapes effectively reduces and balances various aberrations, and the optical system structure is simple and the number of lenses is small, which ensures good imaging during the zoom process. Through the cooperation between the zoom lens group 2, the compensation lens group, and the focusing lens group 4, the axial length of the system and the imaging quality are effectively controlled, making the system structure compact. By adopting the design and adjustment method of internal focusing, not only the stability of the system is guaranteed, but also the environmental adaptation under the full field of view and the small field of view is met. By adopting a sixteen-piece optical structure layout, the design difficulty of the system is reduced, and the continuous zoom of the large-aperture continuous zoom camera optical system is achieved. The optical structure is simple, the aperture is large, the focal length is long, the axial size is short, the stability is high, the environmental adaptability is good, and the image quality is excellent. It can fully match various high-definition imaging components.

[0076] Those skilled in the art will appreciate that the various operations, methods, steps, measures, and schemes in the processes discussed in this application may be alternated, modified, rearranged, decomposed, combined, or deleted.

[0077] The specific implementation methods of the present application described above do not constitute a limitation on the protection scope of the present application. Any other corresponding changes and modifications made according to the technical concept of the present application should be included in the protection scope of the claims of the present application.

Claims

1. A large-aperture continuous zoom camera optical system, characterized in that: It includes a large objective lens group, a variable magnification lens group, a first compensation lens group, a focusing lens group, a first reflecting mirror, a second compensation lens group, a third compensation lens group, a filter lens group and a second reflecting mirror arranged in sequence along the optical axis direction; The large objective lens group is provided with a first lens, a second lens and a third lens in sequence along the optical axis direction; The zoom lens group is provided with a first cemented lens and a sixth lens in sequence along the optical axis direction; The first compensation lens group is provided with a seventh lens and a second cemented lens in sequence along the optical axis direction; The focusing lens group is provided with a third cemented lens; The second compensation lens group is provided with a twelfth lens and a fourth cemented lens in sequence along the optical axis direction; The third compensation lens group is provided with a fifth cemented lens.

2. The large-aperture continuous zoom camera optical system according to claim 1, characterized in that: The first lens comprises a meniscus lens with negative optical power, the second lens comprises a biconvex lens with positive optical power, the third lens comprises a biconvex lens with positive optical power, the material of the first lens comprises H-ZLAF69, the material of the second lens comprises H-FK61B, and the material of the third lens comprises H-FK95N.

3. The large-aperture continuous zoom camera optical system according to claim 1, characterized in that: The first cemented lens includes a meniscus lens with positive focal power and a biconcave lens with negative focal power arranged in sequence along the optical axis direction, the sixth lens includes a meniscus lens with negative focal power, the materials of the first cemented lens include H-ZF88 and H-QK3L, and the material of the sixth lens includes H-LAK52.

4. The large-aperture continuous zoom camera optical system according to claim 1, characterized in that: The seventh lens comprises a biconvex lens with positive focal power, the second cemented lens comprises a meniscus lens with negative focal power and a biconvex lens with positive focal power sequentially arranged along the optical axis, the material of the seventh lens comprises H-LAK11, and the materials of the second cemented lens comprise H-FK95N and H-ZF52GT respectively.

5. The large-aperture continuous zoom camera optical system according to claim 1, characterized in that: The third cemented lens comprises a biconvex lens with positive focal length and a biconcave lens with negative focal length which are sequentially arranged along the optical axis direction, and the materials of the third cemented lens comprise H-FK61B and H-LAK11 respectively.

6. The large-aperture continuous zoom camera optical system according to claim 1, characterized in that: The twelfth lens includes a biconvex lens with positive focal power, the fourth cemented lens includes a biconcave lens with negative focal power and a meniscus lens with positive focal power arranged in sequence along the optical axis, the material of the twelfth lens includes H-ZF88, and the materials of the fourth cemented lens include H-ZLAF69 and H-QK3L respectively.

7. The large-aperture continuous zoom camera optical system according to claim 1, characterized in that: The fifth cemented lens comprises a biconvex lens with positive focal power and a meniscus lens with negative focal power, and the materials of the fifth cemented lens comprise H-QK3L and H-ZF88 respectively.

8. The large-aperture continuous zoom camera optical system according to claim 1, characterized in that: The filter group is provided with a visible light filter, a near infrared filter, a narrow band filter, and a polarized light filter in sequence. The material of the visible light filter includes H-K9L, the material of the near infrared filter includes HB760, the material of the narrow band filter includes HB850, and the material of the polarized light filter includes H-K9L.

9. The large-aperture continuous zoom camera optical system according to claim 1, characterized in that: The axial movement dimension of the variable magnification lens group is greater than the axial movement dimension of the first compensation lens group, and the axial movement range of the focusing lens group is +10mm to -20mm.

10. The large-aperture continuous zoom camera optical system according to claim 1, characterized in that: The focal length of the variable magnification lens group is -80mm<f<-50mm, the focal length of the first compensation lens group is 90mm<f<120mm, and the focal length of the focusing lens group is -150mm<f<-100mm.

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